I like your case. You should write down every single detail while you still remember, including the precise order of questions, answers, actions and reactions, as soon as possible. Have each passenger do the same. Then get a local lawyer to review these facts with you in detail. Fix your tail light!

Your rendition of the facts indicates that you have an arguable defense to the possession charge based on the fact that others possessed the marijuana rather than you. Assuming that the personal searches were not consensual, your passenger has an arguable defense that the police had no justification to detain or search him/her.

Your worst case scenario would appear to be that the district attorney files a case against you, and you fight and lose, and you are found guilty of the possession charge and also found to be in violation of your DUI probation. The consequences would vary depending on the strength of the case against you, any additional DUI or criminal history, the nature and quantity of pot and "other items" found, and the charging and sentencing policies of your local district attorney and the assigned judge, but typically such cases do not involve significant jail (or jail alternative) exposure. Nevertheless, you should definitely explore the defenses discussed above, and any others which might suggest themselves after a thorough review with an experienced local criminal defense attorney.

If you are ever in need of a Sonoma County DUI lawyer, or wish to browse information on DUI law, please feel free to visit my website at http://www.sonomacountyduilawyer.com. Good luck, Jake